<!DOCTYPE html>
<html>
<head> 
<meta charset="utf-8"> 
<title>菜鸟教程(runoob.com)</title> 
</head>
<body>
    <p>
var carname=new String;<br>
var x=      new Number;<br>
var y=      new Boolean;<br>
var cars=   new Array;<br>
var person= new Object;<br>
    </p>

<script>
var person = {
    name : "Bob",
    age : 34,
    weight : "50kg"

}
document.write(person.name + "<br>");
document.write(person["name"] + "<br>");
var person = null;
document.write(person.weight+"<br>");
</script>

</body>
</html>